IL23R

IL23R encodes the interleukin-23 receptor, the IL-23-specific subunit of the heterodimeric IL-23 receptor complex. IL23R pairs with IL12RB1 to form the functional receptor for IL-23 (a p19/p40 heterodimeric cytokine). IL23R is a single-pass type I membrane glycoprotein containing an N-terminal Ig-like domain and two fibronectin type III domains in its extracellular region, a single transmembrane helix, and a cytoplasmic tail bearing tyrosine motifs that recruit JAK2 and STAT3. Upon IL-23 binding, the receptor activates the JAK2/TYK2-STAT3/STAT4 signaling cascade, with predominant STAT3 activation distinguishing IL-23 signaling from IL-12 signaling. IL23R is expressed on Th17 cells, gamma-delta T cells, group 3 innate lymphoid cells, NKT cells, and NK cells, where it drives type 17 immune responses critical for mucosal immunity and defense against extracellular pathogens. The R381Q variant (rs11209026) in the cytoplasmic domain is strongly protective against inflammatory bowel disease and psoriasis, consistent with the causal role of IL-23 signaling in autoimmune inflammation.

Disorders

Relationship is the entry's genetic[].relationship_type. untyped means the entry has a genetic record for the gene but does not type it; its free-text association is shown instead.

• ischemic_bone_necrosis_and_repair via Legg-Calve-Perthes Disease